engineering information technology : Quarter 2

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Antibiotics and Bacteria

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This week I studied bacteria and antibiotics, especially antibacterial consumer products and antibiotics in medicine and farms/ One of the most interesting parts was watching a video about antibiotics in farms and a superbug outbreak at the NIH. It reminded me about the connection between the more abstract-feeling concepts we've been learning and actual human lives.

Bacteria 101

Bacteria are tiny, single-celled microorganisms. They are nearly ubiquitous - existing everywhere in the world except where they cannot find food (sterile locations). Bacteria reproduce by splitting in a process called binary fission. In this process, the DNA in the bacterium divides and replicates, allowing for two copies of the original bacterium. They can be killed by antibiotics, which prevent them from reproducing or outright kill them, but they can also be fought off naturally by our body's immune system.

Bacteria can be both harmful and beneficial to humans. On one hand, bacteria can cause serious infections and even fatal illnesses in people. On the other, they are essential to the proper functioning of our bodies (helping with digestion, populating our gut, etc.) and coming in contact with bacteria can also strengthen our immune system against future diseases or infections. Bacteria also help the environment by functioning as recyclers, breaking down nutrients to make them reusable.

Responsible Use Of Antibiotics in Humans

As I mentioned, bacteria are killed by antibiotics. While they are very useful in this regard when you're suffering from a bacterial infection, they also have some major drawbacks - which means it's incredibly important to use them responsibly. Overuse of antibiotics - when they're used for minor or viral infections - can lead to a much more terrifying phenomenon, one I mentioned in my last post: superbugs, or antibiotic resistance.

Being infected by a superbug is far worse, and has far worse consequences than dealing with the type of minor infection that often cause people to badger doctors for antibiotics. Because of this, it is important for both doctors and patients to understand that antibiotics must be used responsibly - only when absolutely necessary.

Responsible Use of Antibiotics In Animals

This week we watched a video by FRONTLINE explaining the use of antibiotics in farms. There, they are used to enhance growth and keep livestock healthy, especially when animals are crowded together in unsanitary conditions. Initially, nothing seemed wrong with this practice - after all, it was minimizing disease and increasing the production of meat. However, as we began to know more antibiotic resistance and other problems that are increasingly likely to be linked to antibiotic use on farms, scientists began to conduct studies trying to prove a link between the two.

Unfortunately, farmers are not required to release to the public or even to government organizations like the FDA how much and what type of antibiotics they use on their animals. There is a clear connection between this pretty much unregulated use of antibiotics and antibiotic resistance in humans - even more than the antibiotics we prescribe for ourselves, we are consuming huge amounts of antibiotic-tainted meat and, if you live near farms, being exposed to a lot of antibiotics in manure runoff. So, not only is it important that we consciously use prescribed antibiotics responsibly, but we also must be aware of the antibiotics that are used, irresponsibly, in the meat we eat.

Antibacterial Soaps and Products

Beyond medical antibiotics and antibiotics found in farms, there is yet another way we and our environment are exposed to antibiotics, specifically antibacterials. Since the initial surge of popularity for antibiotics, there have also been a large number of other products, ranging from soaps to baby toys, marketing themselves as antibacterial.

I believe we should absolutely minimize the amount of antibacterial soaps and products available on the market, excepting their use in hospitals and food service settings. As we learned in class, many of the compounds used in these products have far more harms than benefits. A recent FDA ban removed nineteen 'antibacterial' chemicals whose use has been proven to risk scrambling hormones in children and promoting antibiotic resistance. This ban seems like a very sensible first step, because while it definitely doesn't make all the changes necessary to prevent antibacterials from endangering human health, it does begin to respond to valid concerns about the safety of the products.

Misconceptions Within Health and Germs

Even though antibiotic resistance and superbugs pose a major threat to global public health, a shocking number of people have blatant misconceptions about the topic and antibiotics in general. Below are three common misconceptions about antibiotics explained.

Misconception #1: Antibiotics treat viral infections like colds or the flu.

Reality: Antibiotics will do nothing to treat colds or the flu, because they are both viral infections and antibiotics kill only bacteria. Using them for viral illnesses can lead to bacterial resistance.

Misconception #2: Antibiotic resistance is when the body no longer responds to drugs.

Reality: Wrong! Antibiotic resistance is when the bacteria are resistant to antibiotics, not the body.

Misconception #3: You can stop taking antibiotics as soon as you feel better.

Reality: Antibiotics need the full prescribed time to work and completely kill of the bacteria. Not doing this may cause relapses and antibiotic resistance.

Pandemic

This week in class we played a board game called Pandemic. Pandemic is a cooperative board game based on the premise that four life-threatening diseases have emerged around the world, each threatening to wipe out a certain region. Every player has a role (e.g. researcher, quarantine specialist, medic) and everyone playing works as a team to cure or even eradicate all four diseases before the time runs out.

It relates to what we're learning about in class because been learning about contagious diseases. public health and the stress of deadly outbreaks (when we watched the clip "Outbreak at the NIH"), and this game showed us that feeling in a way that made it feel very real.

My favorite part of the game was the need for teamwork, because it made it necessary for everyone to calm down and work together to treat and cure the diseases.

If antibiotic resistance was added to the game, it would be a lot harder, because diseases we thought were cured would come back after a few turns. It would also add more complexity to the game, and some player handicaps would make it much harder to win

I think another valuable aspect of Pandemic is that is introduces public health and the difficulty of treating contagious diseases in the form of a fun game. Everyone in my family likes to play Pandemic, but chief among them is my brother, and I think he has learned quite a bit from playing the game. This is what he thinks about Pandemic:

Me: What have you learned from Pandemic?

William: If you don't treat diseases they spread really fast.

Me: What's the biggest challenge?

William: Curing the disease when you only have a few people. Also getting around the world fast enough.

Me: What if after a certain amount of turns a disease became 'uncured?'

William: It'd be super hard. I don't think I'd ever win.

The Miracle Drug And Superbugs

In class this week we read an article called "The Miracle Drug And Superbugs," which was about antibiotics, why we need them, and why we don't. We've been learning about microbes this quarter- previously, we covered fungi, the "supreme recycler," and now we're learning about bacteria and moving into viruses. This article has made me want to learn even more about the history of antibiotics and other medicines - what are the great medical leaps and mistakes of history?

Microbes

The article we read this week was mainly about antibiotics and their effects. However, to understand how antibiotics work, we must also understand what they work against - and what they don't.

The two main types of microbe that cause people to get sick are bacteria and viruses. Aside from that, however, they are different in almost every way.

Bacteria are tiny - single-celled organisms, in fact - but viruses are smaller still, minuscule enough to get inside a single-celled bacterium. Bacteria can live anywhere they can find food (which is to say, almost everywhere), but viruses need a living organism - a host - to survive and reproduce.

Another key difference is that while bacteria are alive, bacteria aren't - they're basically just little pieces of genetic material wrapped in proteins. They can't grow or reproduce unless they've found a cell to use as a host.

As well, from a human perspective, bacteria can be both good and bad, but viruses, to us, are pretty much only bad.

Finally, bacteria can be recognized as invaders by antibiotics and be killed. Viruses, on the other hand, are unable to be detected by antibiotics once they're within a host, and are therefore completely immune to antibiotics.

How Antibiotics Work

So, we know that viruses resist antibiotics, and bacteria don't. But what is an antibiotic, anyway?

Penicillin, the first antibiotic, was discovered in 1928 by Alexander Fleming, and mass produced and put to use by 1940, thanks to Howard Florey and his team of researchers. It was discovered when Fleming left a petri dish of staphylococcus open, to be contaminated by a mold - called penicillium - growing on his windowsill. Fleming noticed that where the bacteria was affected by the mold, it had stopped growing and started dying. This was the beginning of his - and eventually Florey and co.'s - discovery of penicillin, which would lead to the development of a number of other antibiotics.

An antibiotic is a substance that controls/terminates the growth of bacteria. It usually works by preventing the bacteria from reproducing and multiplying, but a few work by just killing the bacteria outright.

When You Don't Need Them

After antibiotics really hit the public in the 1940s, for a while, they became the solution to every problem, big or small, and, importantly, viral or bacterial. Antibiotics were administered even when people didn't need them - when their sickness was caused by a virus instead of bacteria,, when they'd get over it without medicine (strengthening their immune system), or both.

And unfortunately, taking antibiotics is one of the cases for which"you can have too much of a good thing" applies, and we, as a species, have had too much of that good thing.

Taking antibiotics when you don't need them leads to bacterial resistance, also known as antibiotic resistance or just plain "resistance." It's basically when certain bacteria, who've been previously exposed and adapted to an antibiotic, are able to resist it. When the resistance bacteria are among a population, natural selection takes over and eventually the entire population is made up of these resistant bacteria, called superbugs.

Friend or Foe?

When penicillin and other antibiotics first hit the market during World War II, they were lauded as "the miracle drug." Millions of soldiers (in addition to, of course, normal citizens)had been dying due to bacterial infections in the tiniest of cuts. Penicillin perfectly solved the problem, and many people, at the time, found it miraculous.

Now, however, they are no longer known as the miracle drug. While once they were presumed to cure everything, we now know that they sometimes even hurt instead of help, such as with bacterial resistance.

Because of this, antibiotics are now sometimes labeled "bad medicine." Not only does overuse of antibiotics lead to bacterial resistance, but recent research shows that too much exposure to antibiotics and antibacterials can actually stunt your immune system and, as I mentioned last week, antibiotics kill the good bacteria in your gut too, and if you overuse antibiotics even probiotics can only do so much.

Prescribing Medicine

This knowledge of bacteria and viruses and overuse of antibiotics is very applicable to real life situations. For instance, every year, my family gets our share of colds, sore throats, and stomach bugs. We rarely go to the doctor for these illnesses - for that type of sickness, we tend to proceed on the assumption we'll get over it given enough time - but when we do, it's usually because said sickness is much worse than usual, in which case I do expect a prescription for some type of medicine - perhaps antibiotics.

In my case,it's because I believe we shouldn't even go to the doctor unless the cold or virus is bad enough to require treatment, but in general, I think it's a result of our society's tendency to automatically expect a medical/scientific/artificial solutions to our health problems (like I explained last week in terms of probiotics) and tend to undervalue our bodies' built-in protection and natural remedies.

Natural Remedies

Natural remedies are one of the most promoted alternatives to antibiotics.These remedies include compounds found in natural foods, such as Chilean avocados (lowers amount of antibiotics needed when fighting off bacterial infections) and Manuka honey (powerful antibiotic properties, especially against staphylococcus aureus) as well as the broader category of vitamins, such as vitamin C (antiviral and cancer therapy) and vitamin D (fights colds and the flu), or even simple herbs such as garlic, which is antibacterial and antifungal.

These remedies, among others, are advocated as the better, hidden alternative to antibiotics. As I said before, in our society, we tend to expect artificial solutions to our problems - hence our consistent leaning towards antibiotics over natural remedies, even when they appear to have many of the same benefits. However, while the article we read wholeheartedly suggests natural remedies as the perfect alternative to antibiotics, I find that I am slightly skeptical.

I believe the science proving the benefits and effectiveness of natural remedies just as I believe the science that showed first the benefits and then the downsides of using antibiotics.I think that the natural remedies the article professed as "not only the safest, but... also far more effective" are just as effective and perhaps safer than our current antibiotics, however I believe that depending as completely on natural remedies now as we did on antibiotics in the past would be a mistake.

Some natural remedies, such as the Chilean avocado, might, with overuse, face the same issues as antibiotics - after all, isn't it plausible that the bacteria could learn to resist the compound in those avocados as they are learning to resist the chemicals in our antibiotics? Other remedies, such as vitamins C and D, might be too general a solution to work completely in specific cases of bacterial infection. In fact, it seems to me that that type of vitamin is really less of a remedy and more of a preventative measure against such infections

My point is that neither antibiotics nor natural remedies are humankind's perfect solution to bacterial illnesses and infections. However, I do believe that the use of both demonstrates humanity's unique way of adapting in response to bacteria's adaptations - that our own adaptations are actually the only real solution to the bacteria causing illness and adapting to thwart our cures. Antibiotics and natural remedies can both be used in moderation or, in the case of natural remedies, in addition to the new cures and remedies I'm confident our species will find/create in our latest move in the long chain of adaptations that represents our interaction with bacteria and the world around us as a whole.

When microbes like bacteria are metaphorically the very glue that holds our web of life together, we can't expect that just killing as many as we can or eating our vegetables will be our permanent solution. The fact is, when dealing with creatures that are so integral to our ecosystem, there just isn't a permanent solution when some of these creatures harm you instead of help you. We must simply accept that we live in a universe built on change, and that, to survive, we must accept and thrive on that change.

Live Bacteria and Food Makers

This week in class we explored probiotics and food regulations through research and reflection. The research enhanced our learning about bacteria by presenting us with new information about the bacteria naturally in, and sometimes added to, our food. It has made me want to learn more about the specifics of probiotics - which bacteria are the most commonly added to food, what exactly what studies have been conducted supporting or disagreeing with the idea that probiotics actually positively impact your health.

In Live Bacteria, Food Makers See A Bonanza

One of the articles I read this week was called "In Live Bacteria, Food Makers See A Bonanza." It said that companies have discovered that marketing their food products as 'probiotic' has a huge positive impact on their sales, as well as how consumers respond to the sudden surge of probiotic foods.

According to the article, food makers who advertised their foods as "functional" (benefiting your health) found a huge increase in their sales. Because of this, many other companies have picked up this strategy, making probiotic foods than saying that eating those foods will result in improved health. However, the article cautioned that this was really more of a marketing strategy than actual science, saying that probiotics may help your health in general but few specific benefits have been found.

The article also showed contrasting consumer perspectives on probiotics in their food. Some consumers will only buy probiotics if they feel a significant impact on their health. Others, like Susan Kramer, a middle-aged woman quoted in the article, say instead that buying probiotics "just makes her feel good."

This brought up an interesting idea for me, and I explored the idea further in the questions we answered to reflect on the article. Why do we, as a culture, tend to turn to medical solutions to our problems over more natural ones? This question ties directly into probiotics, because I think the reason we buy probiotics is because of that reliance on medical solutions - to us, something marketed as scientifically good for you, or scientifically able to solve your problems is automatically more attractive to consumers than something 'normal.'

Additional Probiotics Can Make You Healthier?

In class this week, we split into groups and researched yogurt, probiotics, and their health benefits, so we could investigate the claim that "additional probiotics in food can make you healthier" and use what we've learned to decide whether or not we agree with this claim.
To me, there are two keywords especially important to pay attention to when considering this claim. Firstly, the statement specifies additional probiotics. However, as the group researching the basics of yogurt learned in our research, yogurt and other fermented foods actually require bacteria (usually from the types called lactobacillus bulgaricus and streptococcus thermophilus in the case of yogurt, for their fermentation process.

This means that yogurt already has live and active cultures in it, which is why yogurt is such a healthy food in general - its beneficial bacteria already give many of the health benefits highlighted in "extra healthy, probiotics added yogurt."

Also, if you compare the health benefits found by the groups researching those of regular yogurt and probiotic yogurt, the most scientifically credited of each tend to match up - they improve digestion and treat bowel conditions like diarrhea and boost your immune system.

This is also the case with most other kinds of fermented foods, which is the main type of food that also claims to have additional probiotics. The fermentation process requires bacteria, so all fermented foods actually already have natural probiotics in them.

Secondly, the claim is that additional probiotics can make you healthier, a very important distinction, as there have been situations where it is truly the more beneficial bacteria the better. The main situation put forward by the group researching the health benefits of probiotics is when someone is taking antibiotics. Antibiotics, while killing the "bad" bacteria in your gut, also take out a lot of the natural beneficial bacteria. Taking probiotics can be extremely effective in repopululating the good bacteria in your gut.

Overall, I think in general that added probiotics do not usually benefit your health in a noticeable way, or in a way beyond the benefits provided by the probiotics naturally in yogurt, but they can be beneficial in specific circumstances, such as when you're taking antibiotics.

Food Packaging and Regulation

The article also brought up the FDA (Food and Drug Administration) and we also explored the administration in our research in class. Their job is particularly relevant to probiotics, as it is their task to define and enforce the line between food and medicine, and foods with added probiotics are, in a way, attempting to be both.

The FDA has a major part in the regulation of what's required to be on food labels. Food labels help you determine whether a food is healthy or not - in fact, they are often the single tool a consumer uses to judge the nutritional value of a food item. Because of this, however, it is extremely important for food labels to actually have the food information consumers need on them.

Unfortunately, when it comes to probiotics, label regulations do not always require enough precision, and food companies are often able to get away with vague statements like "additional probiotics added" without specifying exactly what those probiotics are. When packaging is vague like this, it no longer is a reliable source when judging the health benefits of a food - you need to have all the information to be able to come to an informed conclusion.

Because of this tolerated vagueness, companies are also sometimes able to leave seemingly irrelevant marketing claims unsupported - such as, say, yogurt claiming to improve the consumers' skin and eyesight. I, or likely any other informed consumer, would be very skeptical about buying this. From what I've learned, beneficial bacteria in your food, natural or otherwise, can have many helpful effects - but improving your skin and eyesight isn't one of them. Even when food with added probiotics does have benefits, it is very unlikely for those benefits to extend beyond heightened versions of the benefits given by regular versions of those foods.

The FDA does not take strong enough stand against potentially harmful or even just wasteful products - such as, perhaps, food with added bacteria that may not even be doing anything. They allow food sold through vagueness, imprecision, and even false or unsupported marketing claims to pass into the consumer market.

They can improve in a number of different ways: labels should be more specific, claims should have to cite studies backing them up, and the administrations should just screen more in general, keeping food companies accountable to the safety and well-being of their customers.

Shopping Habits

Probiotics and their (overstated) health benefits are just one example of situations taking advantage of consumers who are just looking for easy ways to stay healthy or consumers who haven't always taken the time to learn about what they're buying. Keeping this in mind, below I have compiled a checklist of some of the things shoppers should keep in mind or do before going grocery shopping.

1. Do your research before going shopping - are there particular brands that are recommended when buying a certain type of food? How does that compare to brands of that product you and your family prefer? This will help you strike a balance between what tastes good, what's best for you, and when a difference in brand just doesn't really matter that much.

2. Think critically about your choices before you make them. This will help you avoid making the impromptu choices that often lead to bad consumer decisions.

3. Read the label before buying the product. While we know that labels aren't always precise or detailed, they are still there as a resource you should take advantage of.

4. Don't let your desire to be healthy drive you to choose foods that advertise artificial health benefits over foods where healthiness is taken for granted, like fresh fruits and vegetables.

5. Finally, remember that your choices are your choices. While it is very useful to have researched a number of different perspectives, it should be from your perspective that you make your decision. You know what's best for yourself.

Keepers of the Biosphere

This week in class we watched a video called "The Keepers of the Biosphere," which showed the importance of microbes and their roles in our biosphere and how that ties into our greater ecosystem and web of life. In class, we've been studying the basics of microbes and how they affect everything around us. This video made me want to learn more about the microbes that weren't mentioned by name in the video, like viruses.

Biosphere

The word biosphere refers to the regions on a planet inhabited by life. It comes from the Greek words bios, meaning life, and sphaira, meaning sphere, so it literally means "life sphere." Similarly, the word atmosphere has the root atmos, or air, the word lithosphere has the root lithos, or stone, and the word hydrosphere has the root hydro, meaning water, so the three words are respectively a planets' "air sphere," "stone sphere" and "water sphere." You could also define the biosphere as the global sum of all ecosystems, which draws more attention to the systems of interdependence required for a biosphere to exist.

In the video, we learned about a group of scientists who designed and executed an experiment called Biosphere 2. The goal of this experiment was to create a self-sustaining, closed system miniature version of our biosphere, complete with seven different biomes and a great variety of flora and fauna, including eight human volunteers. Their creation, if successful, would have been a great asset to organizations hoping to sustain life on another planet, such as Mars.

However, Biosphere 2 failed. After a short period of success, oxygen levels within the closed environment began to drop. Animals died, and the volunteers within began having trouble breathing. Unable to reverse the effect in a way that would not harm the purpose of the experiment without knowing the cause of the problem, the researchers were forced to unseal the experiment and pump in oxygen.

At the time, the scientists did not know what went wrong, but once the experiment failed, research began attempting to determine the cause of the oxygen shortage. We now hypothesize that the oxygen drop was a result of two main issues.

First, microbes. The soil in Biosphere 2 was very rich in nutrients and organic materials, which provided a lot of food for microbes, which multiplied and began to metabolize at an unusually high rate, taking in more oxygen and producing more carbon dioxide.

Now, usually, the plants within the experiment would have been able to compensate for this by consuming the excess carbon dioxide, but this was prevented by the second cause of the drop, the material the walls of the enclosure was made of. The walls surrounding most of the enclosure were made of a particularly calcium hydroxide-rich concrete, which reacted with the excess carbon dioxide in the air to form calcium carbonate and water instead of feeding the plants.

The failure of Biosphere 2 is a valuable learning experience for scientists studying the Earth and our ecosystems, because it reminds of the things often forgotten, all the factors necessary to consider when hoping to sustain life on a smaller scale, and just in general how little we actually know about the world we live in. Before scientists can even consider eventually successfully sustaining or "creating" life on another planet, they must have a much deeper understanding of everything that contributes to creating our biosphere, including that which we cannot see with the naked eye.

The Perfect Recycling Machine

In "Keepers of the Biosphere," the narrator used the term 'perfect recycling machine.' Humans, with our recycled newspapers and reused brown paper bags, like to consider ourselves recyclers. However, we are not the perfect recycling machine - microbes, collectively, are.

Image result for recycling sign microbes

This means they are an integral part of our ecosystem, as their role breaking down waste in our ecosystem and turning it into nutrients is extremely important for maintaining a balance of production and consumption in our biosphere. Calling any individual life form or eve species a perfect recycling machine would be imprecise, however microbes earn this title through their extensive reach. Since the word 'microbe' covers such a huge category of organisms, calling them a perfect recycling machine is referring to the vast network of them that spreads across the Earth, working as a system that is, indeed perfectly suited to recycling.

Because they are so important and so much of our ecosystem, a 'broken' recycling machine would be a disaster for our biosphere, and would basically cause our ecosystem to collapse. A broken recycling machine would cause the rest of the system, from the plants and trees fertilized by the microbe-produced nutrients to the animals (including humans) depending on those plants and trees and many other microbe-affected things to break down as well and would likely lead to mass extinction.

Fungi

Fungi, one of the six major types of microbe (as well as one of the four mentioned in class), is an especially important part of the perfect recycling machine. In fact, the video went even further, crowning fungi 'the supreme recycler,' because of how many ecosystems, especially forests and rain forests, rely on a network of fungi to break down and recycle waste into nutrients, making them an imperative part of the carbon cycle.

According to the video, another role for fungi is to be a kind of link between the microbial and plant worlds, because they are the most similar microbes to plants, visible because of the large quantities they gather in. Some types of fungi also interact with plants, especially trees, in a more directly symbiotic way, intertwining with their roots and providing easier access to certain minerals in return for water and other organic compounds.

Web of Life

The web of life is the system of interdependence and interaction between all living things. It affects everything and everyone - we are all a part of it. The web of life is necessary for an ecosystem because an ecosystem cannot exist at all without the interdependence of living organisms, and it is that interdependence that keeps an ecosystem in balance.

A metaphor often used for the web of life is a literal spiderweb, accurate in that if one part of the web of life frays, as with a spiderweb, the entire thing can unravel. In that image, microbes are at the edges, providing the basis for plants, then animals, and so on and so forth. However, Dan Janzen, in "Keepers of the Biosphere," went a step further, instead imagining the web of life as a three dimensional network, with microbes as the glue holding it all together. This image is an even better metaphor, because the web of life is both incredibly complex and heavily reliant on microbes.

In both of these scenarios, it is vital for the web of life and the ecosystem as a whole to maintain equilibrium. Whether it could metaphorically unravel because of a single frayed thread or fall completely apart without its glue, an imbalanced ecosystem can only lead to a chain reaction of extinctions and disruption. Equilibrium is essential to maintaining a smoothly functioning biosphere, and microbes are essential to that equilibrium.

Glossary:

Microbe: any microscopic organism, as bacteria, protozoa, and some fungi and algae.

Ecosystem: a biological community of interacting organisms and their physical environment.

Web of Life: a system, or a group of interconnected elements, formed by the interaction of a community of organisms with their environment.

Biosphere:
1. the part of the earth's crust, waters, and atmosphere that supports life.

2. the ecosystem comprising the entire earth and the living organisms that inhabit it.

Hydraulics vs. Pneumatics

This week I read an article on pneumatics vs. hydraulics. Once interesting fact I learned was that both pneumatics create a mechanical advantage, which is why they are both commonly used in machines. It is important to read articles like this so we can understand many of the systems that power the machines and vehicles that we see and use in every day life.

Image credit: www.designnews.com

In STEM we've been learning about two different pressure systems, hydraulics and pneumatics. The two systems are similar in that they are both pressure systems used to utilize force. The difference is between them is that hydraulics involve liquids and pneumatics involve gases. Because of how spread out gas molecules are, gas can be compressed, or made more compact. Liquids, on the other hand, are incompressible. For example, if you filled a water bottle all the way to the top and tried to screw on the cap, some of the water would spill out, because the cap would take up a tiny bit of space previously occupied by water, and since water is incompressible and can't be forced to become compact enough to fit in the smaller space, it spills.

Image credit: hendrix2.uoregon.ed

Pressure is defined as the amount of force per unit area. Atmospheric pressure varies depending on how close or far you are from the cor of the Earth. If you are closer to the core of the Earth, then the atmospheric pressure will be greater, because the gravitational pull on the air molecules is stronger and the mass of the air molecules higher up also contribute to the pressure.

Pressure also changes based on the state of the container the substance is in. For example, the pressure in an open container containing liquid only pushes down, and as with the air molecules causing atmospheric pressure, the pressure in an open container increases deeper in the water because of the mass of the water above it. In a closed container, the water is occupying less space than it wants so, so the pressure it applies is spread evenly in all directions.

Mechanical advantage is how a tool or machine can be used to amplify the force put into it. When relating to mechanical advantage, the relationship between cylinder size and force is proportional - applying a small force to the small cylinder results in a large force applied to the large cylinder. However, the relationship between cylinder size and distance is different. The small cylinder has to move a greater distance for the large cylinder to move a smaller distance.

It is important to think about mechanical advantage when we want to create a hydraulic arm so that we can understand and utilize it to increase the efficiency of the arm, and so we can use it to move heavier objects with less force When building the arm, it is useful to use syringes of the same size and differing sizes. If you want the amount of force you put in to be equal to the output force, use two syringes that are the same size. If you want to put in a smaller force for a greater distance to get a greater output force for a shorter distance, use two syringes of differing sizes.

Boat Building

Image credit: www.teachengineering.org

Three objects that look the same in size and shape may not float in the water in the same way. For example, For example, if there were three blocks that were exactly the same size, one made of Styrofoam, one made of hollow wood, and one made of solid wood, each would float, but they would all float in different ways. The Styrofoam would float high in the water, the solid wood float low in the water, and the hollow wood block would float somewhere in between. This is because of how gravity and water pressure affect each block. The Styrofoam block isn't very dense and contains a lot of air, so it doesn't contain much matter. Since its mass is so low, gravity doesn't affect it very much and the water pressure at the surface of the water is enough to keep it afloat.The hollow wood block would be heavier, so it would have to sink farther down in the water before it would find enough water pressure to make it float. The solid wood block would have to sink still further before it would find enough water pressure to counteract the amount of gravity acting on it.

The reason why ships float although they often are made of a material that naturally sinks is mainly due to their shape. When a ball of steel, for example, is dropped in the water, it sinks, because all the force of gravity acting on it focused on one point in the water, so no amount of water pressure can counteract the ball's gravity. But when that same volume of steel is flattened out and shaped into a boat, the amount of gravity acting on it is spread out over a larger surface area, so the water pressure is able to counteract it.

Due to buoyancy, objects displace the same amount of water as their mass and the volume of however much of the object is in the water. If an empty canoe floating on the water weighed 120 pounds, it would displace 120 pounds of water. However, if that same canoe sank, it would displace more than 120 pounds because the canoe would have to weigh more that it did when it floated to sink. The same is true for if the canoe tipped over or filled with water - if it filled with water, that is obviously adding more weight, and if it tipped over it would float lower in the water and therefore displace more water as well.

This week, to show our understanding of buoyancy, density, and particles, we created boats using aluminum foil, modelling clay, and/or Play-doh, all of which are denser than water. The first challenge was to create a boat that floated, but then we were given the additional challenge of making it carry as much weight as possible without sinking. While building my boat, I decided that aluminum foil was the best material, higher sides made the boat stay afloat longer, and larger boats held more weight.

When testing and redesigning my boat I made a number of different changes, including making the shape more elongated, the bottom flatter (it distributed the weight better), the sides higher, and I added a couple extra layers to hold extra air and prevent leaks in the main body of the boat. The design that worked best was my final product. It was the largest yet so that the gravity acting on it was spread over a greater surface area, and higher sides let it sink lower in the water before filling with water. The boat design I tried that worked least well was one of my earliest designs, one that had a more traditional boat bottom, because it forced all the gravity acting on it to focus on less surface area. This made the design sink faster.

During class, we learned about volume, mass, density, and buoyancy through many different types of exploration. After all that we learned, I think it's important to remember these three central points:

Materials that would usually sink in water can be made to float by shaping the material, so that the amount of gravity acting on the material is spread out over a greater surface area.
Where something floats in the water is determined by how far down in the water there is enough water pressure to counteract the gravity acting on the object.
The volume and mass of an amount of water displaced by an object is equal to the volume and mass of the object itself.

These three points can be used to determine how an object floats, why an object floats, and how to make an object float or sink.

Moving Things

Image credit: www.britannica.com

This week I read a selection from books 7 and 8 of Aristotle's Physics. One thing I found interesting was how Aristotle talked about change, and how he said that weight is basically an upward or downward tendency. It is important to read texts like this because it tells us about what some of the first philosophers thought about the subjects we learn about in school.

According to Aristotle, fiery particles naturally move upwards and earthy particles tend to move downwards. Therefore, downwards would be an unnatural direction of movement for something fiery, and upwards would be an unnatural direction of movement for earthy particles.

Image credit: weknowyourdreams.com

Something can be potentially light in one situation and potentially heavy in another situation. This is because of a number of reasons, such as gravity, mass, or, in Aristotle's words, upward or downward tendencies. An example of fluctuating weight would be a pool of water - with the force of gravity acting on it, it remains pulled downward, but if the force of gravity was lessened or removed, it would float upwards.

Image credit: www.public-domain-image.com

When Aristotle spoke of fire and earth having natural movements, I think he is offering an explanation based on principles and causes. He mentioned that they are "forcibly moved by something," which could be a cause, and also says that natural tendencies are caused only by what they already possess in potential, which could be seen as a cause from the fire or earth itself.

Overall, this text was very interesting, because it was intriguing to see a philosopher from such a long time ago thought about the topics he wrote about, and how that related to things like gravity, mass, and density.

To better understand the text, our class put together actions for each paragraph in the excerpt we read, and the complete video can be found below:

Oobleck Lab

Image credit: www.albionlibrary.org

This week I experimented with Oobleck. In class, I have been studying mass, volume, density, and particles. I made Oobleck from cornstarch and water, adding 200 mL of cornstarch to 100 mL of water a little bit at a time. This relates to my learning because we've been learning about how the density of particles affects the state of matter of a substance, and Oobleck is unusual because it has properties of both a solid and a liquid matter.

When you move Oobleck around or apply pressure, the Oobleck feels solid, but when it's still, it melts into liquid. When I looked at the Oobleck, it looked like a blue (because of added food coloring) liquid, and when I shook the plastic bag I had it in, it moved like a liquid. The Oobleck smelled like cornstarch, predictably, but its most interesting feature was definitely how it felt. Through the bag, it felt liquidy, but when I squeezed it, it felt kind of doughy. Once I took some of it out, though, I could make it solid by moving it around but when I set it down, it melted into a waxy puddle.

When I was playing with the Oobleck, the results were mixed. When I poked my finger into the Oobleck slowly, it felt like I was sticking my finger in a liquid. When I poked it quickly, it felt like I was poking a solid. When I was transferring it from one bag to another, it poured like a liquid. I succeeded in rolling the Oobleck into a ball by keeping it constantly in motion, but when I stopped touching it, it became a liquid again. Bouncing the Oobleck was unsuccessful - it melted as soon as it touched the table.

Image credit: www.utwente.nl

My experiments have shown me that Oobleck is a non-Newtonian substance, which means that it's neither a solid nor a liquid, but possesses properties of both. When pressure was applied, or it was kept in motion, the Oobleck was a solid, but when it was left alone, it was more of a liquid. From what I learned in class, I can hypothesize that by applying the pressure that makes it feel solid, I'm actually pushing the particles of the substance closer together. That would explain why it seems to switch between the states of matter. It is a very intriguing substance, and interesting to experiment with.

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